# File lib/nokogiri/html/document.rb, line 50
        def parse string_or_io, url = nil, encoding = nil, options = 2145, &block

          options = Nokogiri::XML::ParseOptions.new(options) if Fixnum === options
          # Give the options to the user
          yield options if block_given?

          if string_or_io.respond_to?(:encoding)
            encoding ||= string_or_io.encoding.name
          end

          if string_or_io.respond_to?(:read)
            url ||= string_or_io.respond_to?(:path) ? string_or_io.path : nil
            return self.read_io(string_or_io, url, encoding, options.to_i)
          end

          return self.new if(string_or_io.length == 0)
          self.read_memory(string_or_io, url, encoding, options.to_i)
        end